In a semiconductor substrate supporting a semiconductor device, the greatest research projects for improving efficiency and properties of the semiconductor device are to reduce crystal defects of a semiconductor layer grown on the substrate and improve crystalline of the semiconductor layer.
A buffer layer may be formed to reduce dislocation defects in a crystal growth process. To form the buffer layer, a process of forming a pattern on a surface of the substrate through a mask formation process and an etching process or a regrowth process may be further required.
Thus, due to the additional process, the manufacturing process may be complicated, and the manufacturing costs may be increased. In addition, the substrate surface may be deteriorated in quality.